1. Technical Field
The present invention relates in general to an improved riser pipe for offshore fluid operations, and in particular to an improved apparatus and method for forming composite pipe structures. Still more particularly, the present invention relates to an improved apparatus and method for securing tubular liners inside composite riser pipes for offshore fluid operations.
2. Description of the Prior Art
Tubular liners for pipes are fairly well known in the prior art. For example, in FIG. 1 of U.S. Pat. No. 4,813,715, a tubular liner 18 is located within a composite drill pipe 10. Each axial end of liner 18 is secured to the ends of drill pipe 10 with a metal connector 30. Another example is illustrated in FIG. 3 of U.S. Pat. No. 5,332,049, wherein a rubber liner 38 is bonded to the interior surface of a composite pipe 34. The ends of liner 38 are secured to pipe 34 with metal connectors 28, 30. In each example, the liners protect the interior surfaces of the composite pipes from pressurized drilling mud and/or other environmental concerns that could damage the non-metallic materials used in the pipes.
Prior art liners for composite pipes are typically bonded to the metal end fittings and/or composite tube of the pipe to form seals. However, adhesives for sealing liners to composite tubes are very sensitive to the manufacturing process. As a result, bonded liners may not be sufficiently reliable for oilfield applications. Moreover, when a liner is bonded, it is permanent and not capable of being reused. Bonded liners also require greater care and assembly time in order to cure the adhesive. Furthermore, the material that is used to form the liner can limit the ability of the liner to form a strong, reliable adhesive bond to the composite pipe and metal end fittings. Thus, an improved apparatus and method for joining liners to composite pipes with metal end fittings is needed to overcome the problems and limitations of the prior art.